With the development of information-oriented societies, research into a flat display device meeting various demands has been gradually increased. As the flat panel display, there are a plasma display panel (PDP), a liquid crystal display (LCD), an organic light emitting diode display (OLED), and the like. In particular, the OLED has advantages of lightness, thinness, and low power consumption and therefore, has been in the limelight as a next-generation display and the LCD has advantages of a large area and a long lifespan and therefore, has been prevalently used.
The above information disclosed in this Related Art section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.